基于多齿刀具切削连续型金属长纤维及高温固相烧结技术,对多孔金属纤维烧结毡(PMFSF)的制造工艺、表征及性能进行研究,并将其应用于被动式自呼吸直接甲醇燃料电池阳极,作为传质控制介质以缓解甲醇穿透而造成的负面影响。与商业化多孔金属纤维烧结毡相比,利用该工艺制得的PMFSF具有较大孔径,孔径分布呈现多峰极化特性,纤维呈随机非规则排列,表面粗糙,因而可获得较大的传质阻力及疏水性。结果表明,采用PMFSF作为电池阳极传质控制介质,能够实现反应物和产物传递过程的平衡管理,因而使电池性能得到显著提升。当PMFSF的孔隙率为70%,甲醇浓度为4mol/L时,电池的性能达到最优。
Fabrication, characterization and performance of a porous metal-fiber sintered felt (PMFSF) based on multi-tooth cutting and solid-phase sintering were studied. The PMFSF was used as the anodic methanol barrier in a passive air-breathing direct methanol fuel cell to mitigate the effects of methanol crossover. Compared with the commercial SUS316L felt made of bundle-drawn fibers, this self-made PMFSF has larger pore diameter, polarized pore distribution, irregular fiber shape, rougher surface, lower mass flow resistance and evident hydrophobicity. The results reveal that the use of a PMFSF significantly enhances the cell performance since it helps to maintain a balance between the reactant and product management while depressing methanol crossover. The PMFSF with a porosity of 70% yields the highest cell performance at a methanol concentration of 4 mol/L.